Column structure and base member

ABSTRACT

In a column structure, a steel column having flanges integrally provided at both ends in a width direction of a web is welded to a base plate. Anchor bolts are anchored to a foundation concrete, and the base plate is fixed to the anchor bolts. The distance in the web width direction between the center axial lines of the anchor bolts is equal to or less than the dimension in the web width direction of the steel column.

TECHNICAL FIELD

The present invention relates to a column structure to which a column member is joined at an upper side of a base member, and to a base member to which a column member is joined at an upper side thereof.

BACKGROUND ART

In Japanese Patent No. 4570139, anchor bolts are anchored to a concrete foundation, a base plate is fixed to the anchor bolts at insertion holes, and a column member is fixed to an upper side of the base plate. The column member is configured from H-section steel integrally provided with flanges at both sides, in a width direction, of a web.

The anchor bolts and the insertion holes are disposed on both outer sides in the web width direction of the column member.

DISCLOSURE OF INVENTION Technical Problem

In consideration of the above circumstances, an object of the present invention is to obtain a column structure which can reduce a dimension, in a web width direction, of a base member, and to obtain a base member which can reduce a dimension, in the web width direction, of a base body.

Solution to Problem

A column structure of a first aspect of the present invention includes: a column member that is integrally provided with a flange at each of both sides in a width direction of a web; a base member to which the column member is joined at an upper side thereof; plural anchor members to each which an anchor portion is attached at a lower end side, each of which is anchored in concrete at the lower end side thereof, and each of which is fixed to the base member at an upper end side thereof, wherein a distance in a web width direction between the plural anchor members is equal to or less than a dimension in the web width direction of the column member.

According to a column structure of a second aspect of the present invention, in the column structure of the first aspect of the present invention, the anchor members are disposed at outer sides in the flange width direction of the column member.

According to a column structure of a third aspect of the present invention, in the column structure of the first aspect or the second aspect of the present invention, an indented portion is provided in a lower side face of the base member.

According to a column structure of a fourth aspect of the present invention, in the column structure of any one of the first aspect to the third aspect of the present invention, the base member includes: a base portion that is provided at each of flange sides; a connection portion that connects together a pair of base portions; and a cutaway portion that is provided between the pair of base portions.

According to a column structure of a fifth aspect of the present invention, in the column structure of any one of the first aspect to the third aspect of the present invention, wherein the base members is provided at each flange side, and a gap is provided between the base members.

According to a column structure of a sixth aspect of the present invention, in the column structure of the fifth aspect of the present invention, the column structure includes a projection portion that is provided at the base member and projects out to a web side of the flange at a lower side of the web.

A base member of a seventh aspect of the present invention includes: a base body to which a column member is joined at an upper side thereof, the column member being integrally provided with a flange at each of both sides in a width direction of a web; and plural fixing portions that are provided at the base body, and that are each fixed to an upper end side of an anchor member to which an anchor portion is attached at a lower end side thereof the anchor member and which is anchored in concrete at the lower end side thereof, wherein a distance in a web width direction between the plural fixing portions is equal to or less than a dimension in the web width direction of the column member.

According to a base member of an eighth aspect of the present invention, in the base member of the seventh aspect of the present invention, the fixing portions are disposed at outer sides in the flange width direction of the column member.

According to a base member of a ninth aspect of the present invention, in the base member of the seventh aspect or the eighth aspect of the present invention, an indented portion is provided in a lower side face of the base body.

According to a base member of a tenth aspect of the present invention, in the base member of any one of the seventh aspect to the ninth aspect of the present invention, the base body includes: a base portion that is provided at each of flange sides; a connection portion that connects together a pair of base portions; and a cutaway portion that is provided between the pair of base portions.

According to a base member of an eleventh aspect of the present invention, in the base member of any one of the seventh aspect to the ninth aspect of the present invention, the base body is provided at each flange side, and a gap is provided between the base bodies.

According to a base member of a twelfth aspect of the present invention, in the base member of the eleventh aspect of the present invention, the base member includes a projection portion that is provided to the base body and projects out to a web side of the flange at a lower side of the web.

Advantageous Effects of Invention

In the column structure of the first aspect of the present invention, the column member, that is integrally provided with the flange at each of both sides in the width direction of the web, is joined to the upper side of the base member. The anchor members each have the anchor portion attached to a lower end side thereof and the anchor members are anchored in concrete at the lower end side thereof, and the base member is fixed at the upper end side of the anchor members.

The distance in the web width direction between the plural anchor members is equal to or less than the dimension in the web width direction of the column member. This thereby can reduce the dimension in the web width direction of the base member.

In the column structure of the second aspect of the present invention, the anchor members are disposed at outer sides in the flange width direction of the column member. This thereby enables the load bearing ability (ability to withstand a bending moment) to be efficiently exhibited by a column setup (which is a transmission portion of a bending moment from the column member to concrete, and which includes the base member and the anchor members).

In the column structure of the third aspect of the present invention, the indented portion is provided in the lower side face of the base member. This thereby enables displacement of the base member in the horizontal direction to be suppressed.

In the column structure of the fourth aspect of the present invention, the base member includes the base portion provided at each of the flange sides, and the connection portion that connects together the pair of base portions.

The cutaway portion is provided between the pair of base portions. This thereby enables the weight of the base member to be reduced. However, due to the web being disposed between the pair of base portions, the load bearing ability of the column setup can be efficiently exhibited.

In the column structure of the fifth aspect of the present invention, the base member is provided at each flange side, and a gap is provided between the pair of base members. This thereby enables each of the base members to be made small, enabling the total weight of the pair of base members to be reduced. Moreover, due to the web being disposed between the pair of base members, the load bearing ability of the column setup can be efficiently exhibited.

In the column structure of the sixth aspect of the present invention, the projection portion, that is provided to the base member, projects out to the web side of the flange at the lower side of the web. This thereby enables the projection portion to be joined to the web, enabling the column member to be joined to the base member strongly.

In the base member of the seventh aspect of the present invention, the column member integrally provided with a flange at each of both sides in the width direction of the web is joined to the upper side of the base body. The anchor members each have the anchor portion attached at the lower end side thereof and the anchor members are anchored in concrete at the lower end side thereof, and the fixing portion of the base body is fixed to the upper end side of the anchor member.

The distance in the web width direction between the plural fixing portions is equal to or less than the web width direction dimension of the column member. This thereby can reduce the dimension in the web width direction of the base body.

In the base member of the eighth aspect of the present invention, the fixing portions are disposed at outer sides in the flange width direction of the column member. This thereby enables the load bearing ability of the column setup (which is a transmission portion of a bending moment from the column member to concrete, and which includes the base body and the anchor members) to be efficiently exhibited.

In the base member of the ninth aspect of the present invention, the indented portion is provided in the lower side face of the base body. This thereby enables displacement of the base body in the horizontal direction to be suppressed.

In the base member of the tenth aspect of the present invention, the base portion is provided at each of the flange sides in the base body, and the connection portion connects together the pair of base portions.

The cutaway portion is also provided between the pair of base portions. This thereby enables the weight of the base body to be reduced. Further, due to the web being disposed between the pair of base portions, the load bearing ability of the column setup can still be efficiently exhibited.

In the base member of the eleventh aspect of the present invention, the base body is provided at each of the flange sides, and the gap is provided between the pair of base bodies. This thereby enables each of the base bodies to be made small, enabling the total weight of the pair of base bodies to be reduced. Further, due to the web being disposed between the pair of base bodies, the load bearing ability of the column setup can still be efficiently exhibited.

In the base member of the twelfth aspect of the present invention, a projection portion provided at the base body projects out to the web side of the flange at the lower side of the web. This thereby enables the project portion to be joined to the web, enabling the column member to be joined to the base member strongly.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-section illustrating a column structure according to a first exemplary embodiment of the present invention, as viewed from the front.

FIG. 2 is a plan view illustrating the column structure according to the first exemplary embodiment of the present invention.

FIG. 3 is a plan view illustrating the column structure according to a second exemplary embodiment of the present invention.

FIG. 4 is a plan view illustrating the column structure according to a third exemplary embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION First Exemplary Embodiment

A cross-section of a column structure 10 according to a first exemplary embodiment of the present invention is illustrated in FIG. 1, as viewed from the front; a plan view of the column structure 10 according to the first exemplary embodiment of the present invention is illustrated in FIG. 2. Note that in the drawings, the arrow FR indicates the forward, and the arrow RH indicates the right direction, and the arrow UP indicates upward.

As illustrated in FIG. 1 and FIG. 2, the column structure 10 according to the present exemplary embodiment is placed on a foundation concrete 12, serving as concrete, with the upper face of the foundation concrete 12 configured in a flat plane shape and the column structure 10 disposed perpendicular thereto along the up-down direction.

Mortar 14 is fixed to the upper face of the foundation concrete 12 as a fixing means, and the mortar 14 is provided in a rectangular shape in plan view.

A metal base plate 16 serving as a base member and as a base body is fixed to the upper face of the mortar 14. The mortar 14 is disposed across the entire lower side of the base plate 16. The base plate 16 is formed in a rectangular plate shape, and the base plate 16 is disposed such that the length direction and width direction thereof are respectively parallel to the front-rear direction and the left-right direction, with the front-rear direction dimension greater than the left-right direction dimension.

Circular shaped fixing holes 18 that each serve as a fixing portion are formed and penetrated through at end portions (corner portions) at the both sides in the front-rear direction and the both sides in the left-right direction of the base plate 16, with the axial direction of the fixing holes 18 parallel to the up-down direction. The positions in the left-right direction of the pair of fixing holes 18 (the center axial lines thereof) on the left side, and the positions in the left-right direction of the pair of fixing holes 18 (the center axial lines thereof) on the right side are respectively aligned with each other; the pair of fixing holes 18 (the center axial lines thereof) on the left side, and the pair of fixing holes 18 (the center axial lines thereof) on the right side are disposed symmetrically to each other about a vertical plane perpendicular to the left-right direction and passing through the center in the left-right direction of the base plate 16. The positions in the front-rear direction of the pair of fixing holes 18 (the center axial lines thereof) at the front side, and the positions in the front-rear direction of the pair of fixing holes 18 (the center axial lines thereof) at the rear side are respectively aligned with each other; the pair of fixing holes 18 (the center axial lines thereof) at the front side, and the pair of fixing holes 18 (the center axial lines thereof) at the rear side are disposed symmetrically to each other about a vertical plane perpendicular to the front-rear direction and passing through the center in the front-rear direction of the base plate 16.

Indented portions 22 are formed to the lower face of the base plate 16 at the periphery of each of the fixing holes 18; the upper face (bottom face) of each of the indented portions 22 is a flat plane shape disposed perpendicular to the up-down direction. The indented portions 22 are formed in triangular shapes in plan view, with a width dimension that gradually increases on progression toward the outer peripheral side of the base plate 16, with the indented portion 22 open to the outer side of the outer periphery of the base plate 16. The peripheral face of each of the indented portions 22 is disposed perpendicular to the horizontal direction, and the base plate 16 center side end peripheral face of each of the indented portion 22 is in the same plane as the peripheral face of the respective fixing hole 18. The mortar 14 fills the whole of the indented portions 22, and the base plate 16 is anchored in the horizontal direction to the mortar 14 by the peripheral faces of the indented portions 22.

Two pairs each of anchor bolts 24 serving as anchor members and serving as second anchor members are respectively fixed to the foundation concrete 12. Circular rod shape anchor bodies 28 are respectively provided at the anchor bolts 24, with the anchor bodies 28 disposed with their axial directions parallel to the up-down direction, and with portions of the anchor bodies 28 other than an upper end portion buried in the foundation concrete 12, with the upper end portion penetrating through the mortar 14.

An anchor nut 30 that has a multifaceted tube shaped external profile and configures an anchor portion, is threaded coaxially on to a lower end portion of each of the anchor bodies 28, and directly above the anchor nut 30, the lower end portion of each of the anchor bodies 28 passes coaxially through a circular ring plate-shaped fixing plate 32 that configures the anchor portion. The anchor nut 30 and the fixing plate 32 are thereby attached to the lower end portion outer periphery of each of the anchor bodies 28. The anchor nut 30 and the fixing plate 32 protrude out to the outer side in the radial direction of each of the anchor bodies 28 and are buried in the foundation concrete 12. The anchor bolts 24 are thereby anchored in the up-down direction to the foundation concrete 12 by the anchor nut 30 and the fixing plate 32.

The upper end portion of the each of the anchor bodies 28 passes through the base plate 16 coaxially to the respective fixing hole 18. A fixing nut 34 that has a multifaceted tube shaped external profile is threaded coaxially on to an upper end portion of each of the respective anchor bodies 28, and directly below the fixing nut 34, the upper end portion of each of the anchor bodies 28 passes coaxially through a circular ring plate-shaped washer 36. The fixing nut 34 and the washer 36 are thereby attached to the outer periphery of the upper end portion of each of the anchor bodies 28. Each of the washers 36 and the base plate 16 is clamped between the fixing nut 34 and the mortar 14, and the base plate 16 is fixed to the anchor bolts 24 at the fixing holes 18.

The lower end of a steel column 38 serving as a column member is welded (joined) to a central side portion of the upper face of the base plate 16, with the length direction of the steel column 38 disposed parallel to the up-down direction.

An elongated rectangular shaped web 38A is provided at the steel column 38. The web 38A is disposed at the center in the front-rear direction of the base plate 16 with its width direction disposed parallel to the left-right direction, with the center in the width direction of the web 38A aligned with the center in the left-right direction of the base plate 16. Elongated rectangular shaped flanges 38B are respectively integrally provided at the both ends in the width direction of the web 38A. The flanges 38B are disposed at the left side portion and the right side portion of the base plate 16, with their width directions parallel to the front-rear direction. The center in the width direction of each of the flanges 38B is connected to the web 38A, and the flanges 38B extend out forward and rearward with respect to the web 38A. The steel column 38 is therefore formed in an H-section as viewed in column structure from the up-down direction. The dimension in the web 38A width direction of the base plate 16 is slightly greater than the dimension in the web 38A width direction of the steel column 38.

At the left side portion and the right side portion of the base plate 16, the center axial lines of the fixing holes 18 and the anchor bolts 24 are disposed at outer sides in the flange 38B width direction of the steel column 38, and the dimension of in the flange 38B width direction of the base plate 16 is equal to or more than the dimension in the flange 38B width direction (the dimension in the flange 38B width direction) of the steel column 38 (for example, 3 times). Moreover, the center axial lines of the fixing holes 18 and the anchor bolts 24 are disposed further inside in the web 38A width direction (including positions facing the flanges 38B in the flanges 38B width direction) than outer side faces in the web 38A width direction of the steel column 38 (faces on the opposite sides of the flanges 38B to the web 38A sides). The distance in the web 38A width direction between the center axial lines of the fixing holes 18 and the anchor bolts 24 (the maximum distance in the web 38A width direction between the center axial lines of the fixing holes 18 and the anchor bolts 24) is equal to or less than the dimension in the web 38A width direction of the steel column 38.

Explanation next follows regarding operation of the present exemplary embodiment.

In the column structure 10 configured as above, the steel column 38 is welded to the upper face of the base plate 16, and in the steel column 38, the flanges 38B are integrally provided at the both ends in the width direction (left-right direction) of the web 38A. The anchor bolts 24 are anchored in the up-down direction to the foundation concrete 12 by the anchor nuts 30 and the fixing plates 32, and the base plate 16 is fixed by the anchor bolts 24 at the fixing holes 18.

The distance in the web 38A width direction between the center axial lines of the anchor bolts 24 (of the fixing holes 18) is equal to or less than the dimension in the web 38A width direction of the steel column 38. This thereby can reduce the amount of the base plate 16 that projects out to the both outer sides in the web 38A width directions with respect to the steel column 38, and can reduce the dimension in the web 38A width direction of the base plate 16. This thereby enables the column structure 10 to be placed even in a case in which it is not possible to make a dimension in the web 38A width direction of the base plate 16 large, such as cases in which the column structure 10 is placed in the vicinity of the outer periphery of a building in a state in which one side in the web 38A width direction of the column structure 10 faces toward the outer periphery of the building.

Moreover, the center axial lines of the anchor bolts 24 (the fixing holes 18) are placed at the outer side of the steel column 38 in the both flange 38B width directions (the front-rear direction), and the dimension in the flange 38B width direction of the base plate 16 is equal to or more than the dimension in the flange 38B width direction of the steel column 38. Thus, even when, such as during an earthquake, a rotation moment acts in the flange 38B width direction (front-rear direction) on the steel column 38 about the lower end thereof and a bending moment acts on the base plate 16 in the flange 38B width direction, consequently, stress (compression force due to the mortar 14 and the foundation concrete 12) acts upward at one side portion in the flange 38B width direction of the base plate 16 and stress (tensile force due to the anchor bolts 24) acts downward at the other side portion in the flange 38B width direction of the base plate 16, it is possible to enlarge a distance in the flange 38B width direction between the portion of the base plate 16 at which the stress acts upward and the portion of the base plate 16 at which the stress acts downward and to enlarge a direction in the flange 38B width direction, between the centers of stress acting upward and stress acting downward on the base plate 16, thereby enabling the stress acting upward and the stress acting downward on the base plate 16 to be made smaller. Moreover, the surface area over which upward stress acts on the base plate 16 can be made large, and hence the upward stress per unit surface area acting on the base plate 16 can be made smaller. This thereby enables a column setup (the portion where a bending moment is transmitted from the steel column 38 to the foundation concrete 12, including the base plate 16, the mortar 14 and the anchor bolts 24) to be efficiently suppressed from exhibiting a drop in load bearing ability (the ability to withstand the bending moment).

Moreover, the base plate 16 is anchored to the mortar 14 in the horizontal direction by the peripheral faces of the indented portions 22. Thus, even in cases in which load acts on the base plate 16 in the horizontal direction, such as during an earthquake, displacement of the base plate 16 in the horizontal direction can be suppressed. This thereby enables the shear capacity of the steel column 38 and the anchor bolts 24 to be raised.

Second Exemplary Embodiment

FIG. 3 is a plan view illustrating a column structure 40 according to the second exemplary embodiment of the present invention.

The column structure 40 according to the present exemplary embodiment is configured substantially the same as the first exemplary embodiment, but differs in the following points.

As illustrated in FIG. 3, in the column structure 40 according to the present exemplary embodiment, pentagonal flat plate shaped base portions 16A are provided at the left side portion and the right side portion of the base plate 16, a rectangular flat plate shaped connection portion 16D is provided between the pair of base portions 16A, and the mortar 14 is disposed across the entire lower side of the pair of base portions 16A and the connection portion 16D. The connection portion 16D is disposed with its length direction parallel to the left-right direction, connecting together the pair of base portions 16A. Cutaway portions 16E are formed between the pair of base portions 16A at both outer sides in the width direction (front-rear direction) of the connection portion 16D. The pair of base portions 16A, the connection portion 16D, and the pair of cutaway portions 16E are disposed symmetrically with respect to a vertical plane that is perpendicular to the left-right direction and passes through the center in the left-right direction of the base plate 16, and are also disposed symmetrically with respect to a vertical plane that is perpendicular to the front-rear direction and passes through the center in the front-rear direction of the base plate 16.

In the base portions 16A, the web 38A sides of the flanges 38B configure projection portions 16C that are formed in pentagonal shapes in plan view, and the inside portions of the projection portions 16C in the web 38A width direction are formed in isosceles triangular shapes in plan view, with portions in the base portions 16A other than inside portions in the web 38A width direction of the projection portions 16C formed as rectangular shapes in plan view. The inside portions in the web 38A width direction of the projection portions 16C have a dimension in the flange 38B width direction that gradually gets smaller on progression toward inside in the web 38A width direction. The cutaway portions 16E have a dimension in the web 38A width direction that gradually gets larger on progression toward the outer side in the flange 38B width direction. Moreover, the inside ends in the web 38A width direction of the base portions 16A (the projection leading ends of the projection portions 16C) are disposed at the lower side of the web 38A.

In the steel column 38, the base portions 16A of the base plate 16 are disposed at the lower side of each of the flanges 38B, and the lower ends of the flanges 38B are respectively welded to the upper faces of the base portions 16A. The projection portions 16C of the base portions 16A are disposed at the lower side of end portions in the width direction of the web 38A, and the lower end of end portions in the width direction of the web 38A are welded to the upper face of the projection portions 16C. The connection portion 16D of the base plate 16 is disposed at the lower side of the central portion of the width direction of the web 38A, and the lower side of the central portion the web 38A width direction is welded to upper face of the connection portion 16D. The position in the front-rear direction of the central portion in the width direction of the connection portion 16D is aligned with the position in the front-rear direction of the center in the thickness direction of the web 38A. The dimension in the width direction of the connection portion 16D is, for example, set at from 3 times to 5 times the dimension in the web 38A thickness direction (in the front-rear direction).

The present exemplary embodiment is also capable of exhibiting similar operation and advantageous effects to those of the first exemplary embodiment.

The base portions 16A are provided at the left side portion and the right side portion of the base plate 16, and the cutaway portions 16E are provided between the pair of base portions 16A.

This thereby enables the weight of the base plate 16 to be reduced, enabling excellent utilization efficiency (yield) of material for the base plate 16.

Moreover, a drop load bearing ability of the column setup at a lower side portion of the web 38A is suppressed by the web 38A. The position between the pair of base portions 16A accordingly imparts only a small influence on the load bearing ability of the base plate 16, enabling the load bearing ability of the column setup to be efficiently exhibited as before, even though the cutaway portions 16E are provided between the pair of base portions 16A.

Moreover, the projection portions 16C of the base portions 16A project out further than the flanges 38B to the web 38A side at the lower side of the web 38A, and the lower end of the end portions in the web 38A width direction are welded to the projection portions 16C. Moreover, at the lower side of the web 38A, the connection portion 16D connects the pair of base portions 16A, and the lower end of the center portion in the width direction of the web 38A is welded to the connection portion 16D. This thereby enables the steel column 38 to be welded to the base plate 16 strongly.

Moreover, at the left side portion and the right side portion (each of the base portions 16A) of the base plate 16, by forming the inside portions in the web 38A width direction of the projection portions 16C as isosceles triangles in plan view, the projection portions 16C are made smaller, and the cutaway portions 16E are made larger. This thereby enables the weight of the base plate 16 to be reduced further, and enabling more excellent utilization efficiency (yield) of material for the pair of base plates 16.

Note that in the present exemplary embodiment the cutaway portions 16E are only provided on the web 38A sides of the flanges 38B. However, the cutaway portions 16E may also be provided on the opposite side of the flanges 38B to the web 38A side.

Third Exemplary Embodiment

A column structure 50 according to the third exemplary embodiment of the present invention is illustrated in a plan view in FIG. 4.

The column structure 50 according to the present exemplary embodiment is configured substantially the same as the first exemplary embodiment, but differs in the following points.

As illustrated in FIG. 4, in the column structure 50 according to the present exemplary embodiment, mortar 14 is provided at the left side and the right side, with the pair of mortars 14 each provided in a pentagonal shape, as illustrated in the plan view.

A base plate 16 is provided in a pentagonal shape, as illustrated in the plan view, at the left side and the right side, with a gap 16B present between the pair of base plates 16, and the mortars 14 on the left side and the right side are respectively disposed across the entire lower side of the left side and the right side base plates 16. The pair of base plates 16 and the gap 16B are disposed symmetrically with respect to a vertical plane that is perpendicular to the web 38A width direction and passes through the center in the width direction (left-right direction) of the web 38A, and are also disposed symmetrically with respect to a vertical plane that is perpendicular to the flange 38B width direction and passes through the center in the width direction (the front-rear direction) of the flanges 38B. Moreover, the shape and the size in the plan view of the pair of base plate 16 and the and the gap 16B are the same as the shape and size of the base plate 16 of the first exemplary embodiment in the plan view, with a pair of first fixing holes 18 similarly formed in the left side and right side base plates 16 to those in the left side portion and the right side portion of the base plate 16 in the first exemplary embodiment.

In the base plates 16, the web 38A sides of the flanges 38B configure projection portions 16C that are formed in pentagonal shapes in the plan view, and the inside portions in the web 38A width direction of the projection portions 16C are formed in isosceles triangular shapes in the plan view, with portions in the base plates 16 other than the inside portions in the web 38A width direction of the projection portions 16C formed as rectangular shapes in the plan view. The inside portions in the web 38A width direction of the projection portions 16C have a dimension in the flange 38B width direction that gradually gets smaller on progression toward inside in the web 38A width direction, and the dimension in the web 38A width direction of the gap 16B gradually gets larger on progression toward outer sides in the flange 38B width direction. The inside ends in the web 38A width direction of the base plates 16 (the projection leading ends of the projection portions 16C) are disposed at the lower side of the web 38A.

In the steel column 38, the base plates 16 are disposed at the lower side of each of the flanges 38B, and the lower ends of the flanges 38B are respectively welded to the upper faces of the base plates 16. The projection portions 16C of the base plates 16 are disposed at the lower side of the end portions in the width direction of the web 38A, and the lower end of end portions in the width direction of the web 38A are welded to the upper face of the projection portions 16C. At the lower side of the central portion in the web 38A width direction, the gap 16B is disposed between the pair of base plates 16, and the lower ends of the center portion in the width direction of the web 38A is not welded to the base plates 16.

The present exemplary embodiment is also capable of exhibiting similar operation and advantageous effects to those of the first exemplary embodiment.

Moreover, the base plates 16 are provided at the lower side of each of the flanges 38B, and the gap 16B is provided between the pair of the base plates 16.

Thus, the plan view size of each of the base plates 16 can be made smaller, enabling the total weight of the pair of base plates 16 to be reduced, thereby enabling excellent utilization efficiency (yield) of material for the pair of base plates 16.

However, due to the web 38A being disposed between the pair of base plates 16, a drop in load bearing ability of the portion of the column setup at the lower side of the web 38A is suppressed from falling by the web 38A, even in cases in which a single base plate 16 is, hypothetically, present at the entire lower side of the steel column 38. Thus the portion between the pair of base plates 16 is a portion that imparts small influence to the load bearing ability of the column setup. This thereby enables the load bearing ability of the column setup to be efficiently exhibited as before, even though the gap 16B is provided between the pair of base plates 16.

Moreover, the projection portions 16C of the base plates 16 project out further than the flanges 38B to the web 38A side at the lower side of the web 38A, and the lower ends of the end portions in the web 38A width direction are welded to the projection portions 16C. This thereby enables steel column 38 to be welded to the base plates 16 strongly.

Moreover, in the base plates 16 on the left side and the right side, the inside portions in the web 38A width direction of the base plates 16 are formed in isosceles triangles in the plan view, such that the projection portions 16C are smaller and the gap 16B is larger. This thereby enables the size of each of the base plates 16 in the plan view to be made even smaller, enabling the total weight of the pair of base plates 16 to be further reduced, and enabling more excellent utilization efficiency (yield) of material for the pair of base plates 16.

Note that in the present exemplary embodiment, the gap 16B is only provided on the web 38A side of the flanges 38B. However, the gap 16B may also be provided on the opposite side of the flanges 38B to the web 38A side.

Moreover, in the first exemplary embodiment to the third exemplary embodiment, the center axial lines of the fixing holes 18 and the anchor bolts 24 are disposed to the outer side in the width direction of the flanges 38B. However, the center axial lines of the fixing holes 18 and the anchor bolts 24 may be disposed at the inside in the width direction of the flanges 38B.

Moreover, in the first exemplary embodiment to the third exemplary embodiment, a pair of each of the fixing holes 18 and the anchor bolts 24 is provided at each of the right side portion and the left side portion of the base plate 16, or to each of the pair of base plates 16. However, it is sufficient for a single, or three or more, of each of the fixing holes 18 and the anchor bolts 24 to be provided at at least one of the right side portion or the left side portion of the base plate 16, or to at least one of the pair of base plates 16.

Moreover, in the first exemplary embodiment to the third exemplary embodiment, all of the anchor bolts 24 are anchored into the same foundation concrete 12. However different anchor bolts 24 may be anchored to separate foundation concretes 12.

EXPLANATION OF THE REFERENCE NUMERALS

-   10 column structure -   12 foundation concrete (concrete) -   16 base plate (base member, base body) -   16A base portion -   16B gap -   16C projection portion -   16D connection portion -   16E cutaway portions -   18 fixing hole (fixing portion) -   22 indented portion -   24 anchor bolt (anchor member) -   30 anchor nut (anchor portion) -   32 fixing plate (anchor portion) -   38 steel column (column member) -   38A web -   38B flange -   40 column structure -   50 column structure 

1. A column structure comprising: a column member that is integrally provided with a flange at each of both sides, in a width direction, of a web; a base member to which the column member is joined at an upper side thereof; and a plurality of anchor members, to each of which an anchor portion is attached at a lower end side thereof, each of which is anchored in concrete at the lower end side thereof, and each of which is fixed to the base member at an upper end side thereof, wherein a distance in a web width direction between the plurality of anchor members is equal to or less than a dimension, in the web width direction, of the column member.
 2. The column structure of claim 1, wherein the anchor members are disposed at outer sides, in a flange width direction, of the column member.
 3. The column structure of claim 1, wherein an indented portion is provided in a lower side face of the base member.
 4. The column structure of claim 1, wherein the base member comprises: a base portion that is provided at each flange side; a connection portion that connects together a pair of base portions; and a cutaway portion that is provided between the pair of base portions.
 5. The column structure of claim 1, wherein the base member is provided at each flange side, and a gap is provided between base members.
 6. The column structure of claim 5, further comprising a projection portion that is provided at the base member and projects out to a web side of the flange at a lower side of the web.
 7. A base member comprising: a base body to which a column member is joined at an upper side thereof, the column member being integrally provided with a flange at each of both sides, in a width direction, of a web; and a plurality of fixing portions that are provided at the base body, and that are each fixed at an upper end side of an anchor member, to which an anchor portion is attached at a lower end side thereof and which is anchored in concrete at the lower end side thereof, wherein a distance in a web width direction between the plurality of fixing portions is equal to or less than a dimension, in the web width direction, of the column member.
 8. The base member of claim 7, wherein the fixing portions are disposed at outer sides, in a flange width direction, of the column member.
 9. The base member of claim 7, wherein an indented portion is provided in a lower side face of the base body.
 10. The base member of claim 7, wherein the base body comprises: a base portion that is provided at each flange side; a connection portion that connects together a pair of base portions; and a cutaway portion that is provided between the pair of base portions.
 11. The base member of claim 7, wherein the base body is provided at each flange side, and a gap is provided between base bodies.
 12. The base member of claim 11, further comprising a projection portion that is provided at the base body and projects out to a web side of the flange at a lower side of the web. 